In conventional jet aircraft, each engine is typically mounted from an aircraft structure, such as a wing or fuselage, by a pylon. The pylon is connected directly to the engine casing so that the loads created by the thrust, the weight of the engine and any air loads acting on the engine during flight are all taken through the engine casing. This results in distortion of the engine casing particularly during aircraft manoeuvres. Rapid wear of the rotor tips occurs due to interference between the rotor tips and the distorted casing. To minimise damage to the rotor tips the clearances between the rotor tips and the casing are increased which increases the fuel consumption of the engine and reduces engine efficiency.